Paper products are commonly formed from pulp fibers, either alone or in combination with other types of fibers. For example, to form a paper web, a dilute aqueous suspension of pulp fibers may be deposited onto a foraminous surface using a headbox. A vacuum device is often located beneath the foraminous surface for removing water away from the web to facilitate web formation. After the web passes over the vacuum device, it is then dried using a conventional drier, such as a through-air dryer.
As a result of a papermaking process, such as described above, the paper web is sometimes formed with an undulating surface that includes multiple ridges and valleys. For example, the foraminous surface on which the pulp fiber suspension is deposited may contain certain features that cause the wet paper web to be formed with ridges and valleys when it passes over the vacuum device. These ridges and valleys can become further defined when the wet web is passed over a dryer that does not utilize compressive forces, such as a through-air dryer.
Although these ridges and valleys can provide many benefits to the resulting paper web, problems sometimes arise when the paper web is incorporated into a paper product. For example, a rolled or stacked paper product containing multiple layers of a paper web having ridges and valleys can possess a certain degree of “nesting”. Specifically, “nesting” occurs when the ridges and valleys of one layer are placed adjacent to corresponding ridges and valleys of another layer, which causes the roll (or stack) to become more tightly packed, thereby reducing roll bulk (increasing density) and making the winding of the product less consistent and controllable. For example, referring to FIG. 3, one example of a nested paper product is illustrated.
As such, a need currently exists for a method to inhibit nesting in paper products.